Mobile SCIP: Managing terminal mobility in heterogeneous networks with the SIP Handover Extension

Advances in Network-centric Warfare require that speech and data must be shared among all tactical levels and across different network domains while the communication still is secured. SCIP (Secure Communications Interoperability Protocol) is an applicationlayer communication protocol designed to ensure secure end-to-end communication. When SCIP is implemented on mobile terminals operating in a heterogeneous environment, handover delays can have severe implications on the quality of service experienced by the end users. In this paper we discuss the implications of handover delays on a SCIP session. We propose the SIP Handover Extension as a means to avoid handover delays by providing seamless handover for SCIP sessions in heterogeneous networks. Implementation and testing show that a SIP user agent supporting the SIP Handover Extension can perform a seamless handover without interfering with the core functions of the SCIP